The Human Bone Cell Production Core of the UAB-Core Center for Musculoskeletal Disorders (UAB-CCMD) will provide human osteoblast progenitor cells and human osteoclast-like cells to UAB-CCMD investigators. This unique Core Facility as a proven track record of success at UAB. Through the UAB-CCD, ongoing support will allow expansion of the program with services provided at no cost to the UAB- CCD pilot project investigators and markedly reduced costs to other UAB-CCMD investigators. The centralization of the production of human bone cells provides efficacy, quality and reflects a commitment of the UAB-CCMD to utilize human derived cells in basic bone research whenever possible. In addition to human osteoblasts and osteoclasts, specialized molecular biology techniques, including tetracycline-regulated stable gene expression and adenovirus-mediated gene expression techniques will be organized in the Core Facility, providing these services in a standardized and coordinated manner to reduce systematic error, and improve efficiency. The core facility will reduce developmental and production costs, and improve the overall quality associated with human bone cells preparation and related stable gene expression. This proposal will support the following activities: 1. PREPARATION AND PURIFICATION STRO-1 POSITIVE OSTEOBLASTS FROM HUMAN BONE; 2. PREPARATION OF HUMAN OSTEOCLASTS; 3. STABLE EXPRESSION OF SPECIFIC GENES IN BONE CELLS: a. Adenovirus expression-vector construction b. Tetracycline-regulated gene expression.